Technical description
No Heating demand from external controls 230V
What causes this fault?
This status occurs because the boiler is powered on and ready to work, but it hasn't received a 'request' for heat from your wall thermostat or timer. It is physically blocked from firing up because your external controls are telling it that the house is already at the desired temperature or that the heating is scheduled to be off.
This code is frequently seen during the transition into autumn when homeowners first try to turn their heating on, only to find the thermostat batteries have died over the summer.
DIY fix possible
Check that your room thermostat is turned up higher than the current room temperature.Ensure your heating programmer or central heating clock is set to an 'On' period.Check if any wireless thermostats have run out of batteries and replace them if necessary.